Alert pt by 2 same online bookings for 1 pt

when people book online, they sometimes book the same appointment they had already, but forgot they had (i guess). It would be great for the pt to get an alert when they have a booking on that same day already (or a time frame we can all set for ourselves). And when they finish the booking online that they get an overview of their appointments, that they can check for themselves, that they didn't double book themselves, or to check wether they put all the other apps in their agenda. Obviously.. if there would be an app ;-), this could all be done and checked from and within the app. Yet probably not all will have the app.